1. Field of the Invention
The present invention relates to connection systems for Barge-Tug connections in which a tug pushes a notched barge. More particularly the present invention relates to a connection and tensioning device for the "pushing lines" which connect notched barges and tugs together preventing separation in adverse sea conditions while allowing relative movement between the tug and the barge and further allowing easy quick release of the pushing lines in emergencies without human intervention on deck.
2. General Background and Prior Art
It is well known in the marine art to secure the tug in the notch of the barge by using pushing lines. Most of the systems in present use look similar.
One end of a heavy cable, generally a wire rope, is secured with a shackle to the transom of the barge on each side. The other end of this cable, called the pushing line, runs over a large sheave pinned on the aft deck of the tug, close to the bulwark, and is then secured either to the deck of the ship or the towing winch, sometimes through some kind of device giving some elasticity to the assembly.
Generally all systems are built on these present principles and differ only by their components. Most of these prior art systems have the same drawbacks. The pushing lines at sea are taut and slack alternatively, due to relative motions of the tug and barge, and snap by snatching when the sea deteriorates. The handling of those lines is very clumsy and there is generally no safe emergency release system.
Those systems of the prior art, although in use for many years, have not been greatly improved since the tugs were pushing only in relatively good weather.
The sizes of tugs and barges are now increasing sensibly as well as the necessity to keep on pushing in adverse conditions. Some recent technological improvements on the fender system of the tug allow the tug to stay in the barge up to fifteen (15) foot seas and there is a demand for improved pushing lines. An increase in the size of the actual system becomes a problem in that large systems are impossible to handle by the crew members and too expensive.